The sintering performance and application effect of electrode paste in electric arc furnace
Electrode paste, also known as self-baking electrode, is an indispensable and important material in mineral heat furnaces.It relies on the heat in the mine heat furnace to complete the roasting, and its sintering performance and application effect are directly related to the production efficiency and product quality of the electric arc furnace.This article will discuss in detail the sintering properties and application effects of electrode paste in electric arc furnaces.
Sintering properties of electrode paste
The sintering performance of the electrode paste is the key to whether it can play an effective role in the electric arc furnace.The sintering process of electrode paste is a complex physical and chemical process, involving a variety of factors, such as the quality of raw materials, the selection of binders, and the sintering temperature.
Raw material quality: The main raw materials for electrode paste include anthracite coal, metallurgical coke, artificial graphite crushed and petroleum coke.The quality and ratio of these raw materials directly affect the sintering performance of the electrode paste and the quality of the final electrode.For example, anthracite coal is the main part of the electrode paste, which becomes the skeleton of the electrode after firing, and the addition of artificial graphite can increase the conductivity and thermal stability of the product.
Choice of binder: Binder plays a vital role in the sintering process of electrode paste.Commonly used binders are coal asphalt and coal tar.These binders can be converted into solid coke during the sintering process, which plays a coking role and forms a self-burning electrode as a whole.The softening point and content of coal asphalt have a significant impact on the sintering performance of the electrode paste.
Sintering temperature: The sintering temperature of the electrode paste is a key factor affecting its sintering performance.Below 300℃, the electrode paste is in a plastic state, with the lowest mechanical strength, and it is prone to soft break accidents.As the temperature rises, the volatiles of coal asphalt are discharged, and the remaining coal asphalt is carbonized to form a network, which is fused with various electrode paste raw materials, and the mechanical strength gradually increases.When the temperature reaches above 1500℃, the mechanical strength of carbon materials is still increasing, while the mechanical strength of other materials such as heat-resistant alloys drops sharply.
Application effect of electrode paste
The application effect of electrode paste in electric arc furnace is mainly reflected in the following aspects：
Electrical conductivity: The electrode paste must have good electrical conductivity to ensure that the electric arc furnace can work normally.The electrode paste made of carbon material can withstand arc temperatures up to 3500℃ and only oxidizes slowly, so it is very suitable as an electrode material for electric arc furnaces.
Oxidation resistance: The electrode paste must have good oxidation resistance at high temperatures to prevent the electrode from oxidizing and consuming too quickly.A smaller porosity can make the electrode in the heated state oxidize slowly and extend the service life of the electrode.
Mechanical strength: The electrode paste must form a strong electrode during the sintering process to withstand the influence of mechanical and electrical loads and prevent the electrode from breaking.The higher mechanical strength can also ensure that the electrode is not easily damaged when the charge collapses.
Sintering speed: The sintering speed of the electrode paste has an important impact on the production efficiency of the electric arc furnace.The airtight paste has good sintering properties and fast sintering speed, and is suitable for airtight ore heating furnaces.The sintering speed of standard paste is slower, but the price is low, and it is suitable for open calcium carbide furnaces.
Selection and optimization of electrode paste
In practical applications, the selection of electrode paste needs to be determined according to the type of electric arc furnace, smelting conditions and production requirements.For large-scale closed mineral heat furnaces, a closed paste with good sintering properties should be selected; for open calcium carbide furnaces, a standard paste with a lower price can be selected.
In addition, the control items such as volatiles, ash and moisture of the electrode paste also have an important impact on its performance.The volatile content must be controlled within a certain range, otherwise it will cause problems such as the electrode is not easy to sinter, poor strength, and easy to break soft or hard.The lower the ash content, the better, but it is limited by the source of raw materials, and the general requirement is not higher than 5%.
The sintering performance and application effect of electrode paste in electric arc furnace are directly related to the production efficiency and product quality of electric arc furnace.By optimizing the quality of raw materials, selecting suitable binders, controlling the sintering temperature, and rationally selecting the type of electrode paste, the sintering performance and application effect of the electrode paste can be significantly improved, and it provides a strong guarantee for the efficient and stable operation of the electric arc furnace.
